1. Field of the Invention
The present invention relates to a 3-dimensional display device, and more particular to a 3-dimensional display device having improved photo-efficiency and brightness.
2. Discussion of the Related Art
Due to the high speed telecommunication network, telecommunication equipment has been developed to a digital terminal which is used for a multi-media service such as text message service, voice service, and image service as well as telephone. This telecommunication equipment may be developed to the 3-dimensional (dimensional) real telecommunication service.
A 3-dimensional image is realized by the principle of stereo-sight in two eyes. Since the two eyes of a human are apart from each other at 65 mm, the binocular parallax is most important thing in the 3-dimensional image. When the left eye and the right eye see respectively different 2-dimensional images, each 2-dimensional is transmitted to the brain through a retina, and the brain combines the two 2-dimensional images to recognize the 3-dimensional image.
This function is called as stereography. There some methods for 3-dimensional image using the 2-dimensional, for example, the 3-dimensional image method using an anaglyphoscope, the 3-dimensional image method without anaglyphoscope, and a holographic method.
Of these methods, there are some problems in the 3-dimensional image method using an anaglyphoscope and the holographic method. That is, in the 3-dimensional image method using an anaglyphoscope, for a many people to see the 3-dimensional image at the same time, they must put on the anaglyphoscope glasses. In the holographic method, although users may see the 3-dimensional image at all the directions, there are some technical problems and the space required for holographic system may be increased.
There are not these problems in the 3-dimensional image method without anaglyphoscope and thus this method has been adapted to the 3-dimensional display device. Specially, the parallax 3-dimensional image method that the stereo images for the right eye and the left eye are separated to see the 3-dimensional image is mainly used.
In the parallax method, the image having image information for the right and left eyes is superposed with the slits arranged in the horizontal direction is superposed to separate the composed 3-dimensional image into the right image and the left image. By this separation, the user is able to see the 3-dimensional image. In this method, the display device should include the display panel for display image and a parallax barrier having slits.
Hereinafter, we will describe the related parallax 3-dimensional display device accompanying FIG. 1. At that time, the liquid crystal display panel is described as the main display panel.
As shown in FIG. 1, the liquid crystal display panel 10 includes a plurality of left eye pixels L and right eye pixels R arranged alternatively each other. A backlight 20 is disposed in the rear of the liquid crystal display panel 10 to supply the light to the liquid crystal display panel 10. The parallax barrier 30 is disposed between the liquid crystal display panel 10 and the viewer 40 to transmit or block the light transmitting the liquid crystal display panel 10. In the parallax barrier 30, a plurality of slits 32 and barriers 34 are alternatively formed in the stripe shape to transmit and block respectively the light from the left eye pixels L and the right eye pixels R.
In the related display device, the light L1 transmitting the left eye pixels L of the liquid crystal display panel 10 from the backlight 20 is reached to the left eye of the viewer 40 through the slits 32 of the parallax barrier 30, while the light L2 transmitting the left eye pixels L of the liquid crystal display panel 10 and to be reached to the right eye of the viewer 40 is blocked by the barrier 34 of the parallax barrier 30.
Further, the light R1 transmitting the right eye pixels R of the liquid crystal display panel 10 from the backlight 20 is reached to the right eye of the viewer 40 through the slits 32 of the parallax barrier 30, while the light R2 transmitting the right eye pixels R of the liquid crystal display panel 10 and to be reached to the left eye of the viewer 40 is blocked by the barrier 34 of the parallax barrier 30.
Accordingly, the light L1 and R2 transmitting the left eye pixels L and the right eye pixels R is respectively reached to only the left eye and the right eye of the viewer 40. Since there is the sufficient parallax information between the light L1 and R2 transmitting the left eye pixels L and the right eye pixels R, the viewer 40 can perceive the parallax between the light L1 and R2 transmitting the left eye pixels L and the right eye pixels R and thus see the 3-dimensional images.
In the related parallax 3-dimensional display device, however, since the light is passing only the slit 32 of the parallax barrier 30 and blocked in other region by the barrier 34, the transmittance may be decreased and the brightness may be also decreased.
Further, since only a 3-dimensional image can be displayed in the related parallax 3-dimensional display device, it is impossible to watch the 2-dimensional image with this device. Actually, the present images are mainly displayed by the 2-dimensional display device. Thus, if only a 3-dimensional image can be displayed by the 3-dimensional display device, the user has to buy an additional display device to watch the 2-dimensional image.